fs/ocfs2/sysfile.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /* -*- mode: c; c-basic-offset: 8; -*-
   3  * vim: noexpandtab sw=8 ts=8 sts=0:
   4  *
   5  * sysfile.c
   6  *
   7  * Initialize, read, write, etc. system files.
   8  *
   9  * Copyright (C) 2002, 2004 Oracle.  All rights reserved.
  10  */
  11
  12 #include <linux/fs.h>
  13 #include <linux/types.h>
  14 #include <linux/highmem.h>
  15
  16 #include <cluster/masklog.h>
  17
  18 #include "ocfs2.h"
  19
  20 #include "alloc.h"
  21 #include "dir.h"
  22 #include "inode.h"
  23 #include "journal.h"
  24 #include "sysfile.h"
  25
  26 #include "buffer_head_io.h"
  27
  28 static struct inode * _ocfs2_get_system_file_inode(struct ocfs2_super *osb,
  29                                                    int type,
  30                                                    u32 slot);
  31
  32 #ifdef CONFIG_DEBUG_LOCK_ALLOC
  33 static struct lock_class_key ocfs2_sysfile_cluster_lock_key[NUM_SYSTEM_INODES];
  34 #endif
  35
  36 static inline int is_global_system_inode(int type)
  37 {
  38         return type >= OCFS2_FIRST_ONLINE_SYSTEM_INODE &&
  39                 type <= OCFS2_LAST_GLOBAL_SYSTEM_INODE;
  40 }
  41
  42 static struct inode **get_local_system_inode(struct ocfs2_super *osb,
  43                                              int type,
  44                                              u32 slot)
  45 {
  46         int index;
  47         struct inode **local_system_inodes, **free = NULL;
  48
  49         BUG_ON(slot == OCFS2_INVALID_SLOT);
  50         BUG_ON(type < OCFS2_FIRST_LOCAL_SYSTEM_INODE ||
  51                type > OCFS2_LAST_LOCAL_SYSTEM_INODE);
  52
  53         spin_lock(&osb->osb_lock);
  54         local_system_inodes = osb->local_system_inodes;
  55         spin_unlock(&osb->osb_lock);
  56
  57         if (unlikely(!local_system_inodes)) {
  58                 local_system_inodes =
  59                         kzalloc(array3_size(sizeof(struct inode *),
  60                                             NUM_LOCAL_SYSTEM_INODES,
  61                                             osb->max_slots),
  62                                 GFP_NOFS);
  63                 if (!local_system_inodes) {
  64                         mlog_errno(-ENOMEM);
  65                         /*
  66                          * return NULL here so that ocfs2_get_sytem_file_inodes
  67                          * will try to create an inode and use it. We will try
  68                          * to initialize local_system_inodes next time.
  69                          */
  70                         return NULL;
  71                 }
  72
  73                 spin_lock(&osb->osb_lock);
  74                 if (osb->local_system_inodes) {
  75                         /* Someone has initialized it for us. */
  76                         free = local_system_inodes;
  77                         local_system_inodes = osb->local_system_inodes;
  78                 } else
  79                         osb->local_system_inodes = local_system_inodes;
  80                 spin_unlock(&osb->osb_lock);
  81                 kfree(free);
  82         }
  83
  84         index = (slot * NUM_LOCAL_SYSTEM_INODES) +
  85                 (type - OCFS2_FIRST_LOCAL_SYSTEM_INODE);
  86
  87         return &local_system_inodes[index];
  88 }
  89
  90 struct inode *ocfs2_get_system_file_inode(struct ocfs2_super *osb,
  91                                           int type,
  92                                           u32 slot)
  93 {
  94         struct inode *inode = NULL;
  95         struct inode **arr = NULL;
  96
  97         /* avoid the lookup if cached in local system file array */
  98         if (is_global_system_inode(type)) {
  99                 arr = &(osb->global_system_inodes[type]);
 100         } else
 101                 arr = get_local_system_inode(osb, type, slot);
 102
 103         mutex_lock(&osb->system_file_mutex);
 104         if (arr && ((inode = *arr) != NULL)) {
 105                 /* get a ref in addition to the array ref */
 106                 inode = igrab(inode);
 107                 mutex_unlock(&osb->system_file_mutex);
 108                 BUG_ON(!inode);
 109
 110                 return inode;
 111         }
 112
 113         /* this gets one ref thru iget */
 114         inode = _ocfs2_get_system_file_inode(osb, type, slot);
 115
 116         /* add one more if putting into array for first time */
 117         if (arr && inode) {
 118                 *arr = igrab(inode);
 119                 BUG_ON(!*arr);
 120         }
 121         mutex_unlock(&osb->system_file_mutex);
 122         return inode;
 123 }
 124
 125 static struct inode * _ocfs2_get_system_file_inode(struct ocfs2_super *osb,
 126                                                    int type,
 127                                                    u32 slot)
 128 {
 129         char namebuf[40];
 130         struct inode *inode = NULL;
 131         u64 blkno;
 132         int status = 0;
 133
 134         ocfs2_sprintf_system_inode_name(namebuf,
 135                                         sizeof(namebuf),
 136                                         type, slot);
 137
 138         status = ocfs2_lookup_ino_from_name(osb->sys_root_inode, namebuf,
 139                                             strlen(namebuf), &blkno);
 140         if (status < 0) {
 141                 goto bail;
 142         }
 143
 144         inode = ocfs2_iget(osb, blkno, OCFS2_FI_FLAG_SYSFILE, type);
 145         if (IS_ERR(inode)) {
 146                 mlog_errno(PTR_ERR(inode));
 147                 inode = NULL;
 148                 goto bail;
 149         }
 150 #ifdef CONFIG_DEBUG_LOCK_ALLOC
 151         if (type == LOCAL_USER_QUOTA_SYSTEM_INODE ||
 152             type == LOCAL_GROUP_QUOTA_SYSTEM_INODE ||
 153             type == JOURNAL_SYSTEM_INODE) {
 154                 /* Ignore inode lock on these inodes as the lock does not
 155                  * really belong to any process and lockdep cannot handle
 156                  * that */
 157                 OCFS2_I(inode)->ip_inode_lockres.l_lockdep_map.key = NULL;
 158         } else {
 159                 lockdep_init_map(&OCFS2_I(inode)->ip_inode_lockres.
 160                                                                 l_lockdep_map,
 161                                  ocfs2_system_inodes[type].si_name,
 162                                  &ocfs2_sysfile_cluster_lock_key[type], 0);
 163         }
 164 #endif
 165 bail:
 166
 167         return inode;
 168 }
 169